Viral and Bacterial Diseases. Part 1 Skin, Respiratory, and Alimentary Infections

Transcription

1 Viral and Bacterial Diseases Part 1 Skin, Respiratory, and Alimentary Infections

2 Bacterial Diseases of Skin Staphylococcus aureus folliculitis inflammation of a hair follicle, Boils (furuncles) single localized inflammation, carbuncles series of boils draining pus, scalded skin syndrome skin peels off the body as if it had second degree burns caused by a toxin, MRSA Methicillin Resistant Staphylococcus Aureus Streptococcus pyogenes Impetigo blisters that weep plasma and form golden colored crusts

3 Scalded skin syndrome and Impetigo Figure

4 Bacterial Skin Infections Rickettsia Rickettsii Rocky Mountain Spotted fever transmitted by tick faint spots cover extremities- spreads to rest of body- becomes hemorrhagic due to blood vessel damage Borelia burgdorferi Lyme Disease Disease transmitted by tick bulls-eye rash eye rash ECM (erythema( chronicum migrans red persisting expanding rash)

5 Rocky mountain spotted fever Figure 22.8 Dermacentor andersoni wood tick

6 Figure 22.9 Rickettsia rickettsii

7 Reported cases of Rock Mountain spotted fever Figure 22.10

8 Lyme disease Figure

9 Reported cases of Lyme disease

10 Viral Skin Infections Varicella-Zoster Chicken Pox-Shingles (zoster) Rubeola Chicken Pox - raised red bumps all over the body Shingles raised vesicles starting along trigeminal nerves Very contagious Varicella vaccine Measles Rubella - fine red rash starts on forehead and spreads to rest of body Koplick spots in mouth look like red grains of sand at base of tongue MMR vaccine 400,000 cases in 60 s in US now less than 100/year German Measles - R in TORCH (congenital diseases) and MMR vaccine) similar rash to measles no Koplick spots however.

11 Chickenpox Shingles Figure Figure 22.18

12 Measles (rubeola( rubeola) Koplick Spots Figure Figure 22.21

13 Electron micrograph of Varicella zoster virus Figure 22.19

14 German measles (rubella) Figure 22.23

15 Reported cases of German measles Figure 22.24

16 Viral Skin Infections Erythema infectiosum Slapped Cheek or Fifth s disease red rash on face Exanthem subitum Roseola high fever (105 F) and seizures followed by red rash on chest and abdomen HPV Human Papilloma Virus causes common warts benign bumps of out of control growth in each spot.

17 Wart virus - papillomaviruses Figure 22.25

18 Bacterial Upper Respiratory Infections Streptococcus pyogenes Strep Throat (pharyngitis( pharyngitis) beefy red, raw, throat with white pustules fever over 101 F. Corynebacterium diphtheriae Diphtheria formation of whitish-gray pseudomembrane on throat and mucous membrane - powerful toxin (since it is an enzyme can be re- used) Haemophilus influenzae pink-eye - conjunctivitis Streptococcus pneumoniae sinus infections and ear-aches aches

19 Streptococcus pyogenes Figure 23.2

20 Complications Rheumatic heart disease Figure 23.4

21 Corynebacterium diphtheriae Figure 23.5

22 Otitis media Figure 23.7

23 Viral Upper Respiratory Infections Common cold - Rhinovirus (a naked RNA virus - very small) - scratchy throat, nasal discharge, malaise, headache, cough Adenoviral Pharyngitis - Adenovirus (a naked DNA virus with spikes) - presents with fever (unlike cold), very sore throat, severe cough, swollen lymph nodes on neck, pus on tonsils and throat, and conjunctivitis.

24 Rhinovirus Figure 23.8

25 Bacterial Pneumonia Infections Streptococcus pneumoniae encapsulated gram +; secondary, 1-31 days, severe, vaccine available Klebsiella pneumoniae - gram -; opportunistic, days, less severe, no vaccine Mycoplasma pneumoniae no cell wall; primary, weeks, less severe, no vaccine

26 Streptococcus pneumoniae Figure 23.9

27 Chest x-ray x of pneumococcal pneumonia Figure 23.10

28 Mycoplasma pneumoniae Figure 23.12

29 Klebsiella pneumoniae Figure 23.11

30 Bacterial- Other Lower Respiratory Infections Bordetella pertussis- Whooping Cough - persistent staccato cough followed by whoop to get air Mycobacterium tuberculosis TB Acid fast bacteria, forms plaques on lungs (seen by X-X Rays) Legionella pneumophilia Legionaire s disease, Pontiac Fever Transmitted by aerosolized water droplets cooling tanks for AC systems

31 Bordetella pertussis Figure 23.13

32 Mycobacterium tuberculosis Figure 23.17

33 Tuberculosis lesion Figure 23.18

34 Figure Tuberculin test

35 Legionella pneumophila fluorescent stain Figure 23.20

36 Influenza Influenza can be deadly antigenic drift changes in Hemagglutinin and Neuramidase spikes yearly; antigenic shift major changes when animal flu virus co-infects someone and a segment of RNA genome is swapped.) Symptoms: Fever, muscle aches, lack of energy, headache, sore throat, nasal congestion, cough.

37 Antigenic shift Figure 23.22

38 RSV Respiratory Syncytial Virus affects children mostly Cells of lungs fuse to form a giant Syncia Syncia cell decreases gas transport- Symptoms include runny nose, cough, fever, wheezing, difficulty breathing, and a dusky color (due to less oxygen intake).

39 A cold for all seasons

40 HPS Hantavirus Pulmonary Syndrome aka Sin Nombre virus (no-name name virus) affected 4 corners area of SW United States in 1993 transmitted by mouse droppings. Symptoms: fever, muscle aches, vomiting, diarrhea, cough, shortness of breath, shock. 40% mortality rate.

41 Cases of Hanta virus Figure 23.23

42 Bacterial Upper Alimentary Infections Streptococcus mutans -Dental caries (tooth decay) - requires sugar, acidic environment and tooth to cause the decay Treponema, Fusobacterium, Prevotella - Trench mouth - abrupt onset, fever, bleeding, painful gums, and foul odor. Helicobactera pylori - stomach ulcers - bacteria produces an alkaline environment to survive in gastric juices (very acidic environment)

43 Scanning electron micrograph - dental plaque Figure 24.3

44 Periodontal disease Figure 24.5

45 Figure 24.6 Trench mouth

46 Helicobacter pylori Figure 24.7

47 Gastric ulcer formation Figure 24.8

48 Viral - Upper Alimentary Infections Herpes Simplex I Cold Sores Mumps swelling of the parotid gland MMR vaccine

49 Herpes simplex I cold sores Figure 24.9

50 Figure Mumps

51 Reported cases of mumps Figure 24.11

52 Bacterial Lower Alimentary Infection Vibrio cholerae Cholera contaminated water - huge loss of water due to changes in electrolytes caused by the cholera toxin typically 20 L of water a lost each day - bacteria adhere tightly to intestines Campylobacter jejuni Food poisoning from fowl or unpasteurized milk. diarrhea and vomiting with severe abdominal cramping

53 Scanning electron micrograph of Vibrio choerae Figure 24.12

54 Scanning electron micrograph of Campylobacter jejuni Figure 24.15

55 Salmonella Salmonella enterica Typhi Typhoid Fever (5 F s of transmission - food, flies, feces, fingers, fomites) food handlers that don t wash hands high fever, delirium, abcesses,, septicemia, shock, but no diarrhea. Salmonella enterica Typhimurium Salmonellosis transmitted by products with raw eggs (cookie dough) also transmitted by pets such as turtles, iguanas, baby chickens, and ducks. most common symptom - diarrhea

56 Bacterial- Lower Alimentary Infections Shigella Shigellosis Bacterial Dysentery other symptoms: headache, vomiting, fever, stiff neck, convulsions, and joint pain spread by oral-fecal route humans are the only source transmitted by fecally contaminated food or water. Escherichia Most are normal flora, but several groups are pathogenic Enterotoxigenic (ETEC), Enteroinvasive (EIEC), Enteropathogenic (EPEC), and Enterohemorrhagic (EHEC). An EHEC group - E. coli O157:H7 - caused the Jack in the Box hamburger infections). Hemolytic Uremic Syndrome causes blood cells to lyse in small blood vessels causes anemia and kidney failure.

57 Pathogenesis of shigellosis Figure 24.14

58 Mechanisms of Pathogenesis for Enterobacteriacae Attachment must attach so they are not swept away Toxin Production Toxins will either 1)increase secretion of water and electrolytes or 2) destroy cells by stopping protein synthesis. Cell Invasion Activates endocytosis and avoids lysozyme in order to multiply within the cell Loss of Microvilli Substances enter the host cell and rearrange the actin to form tails in order to move throughout the cytoplasm.

59 Viral Lower Alimentary Infections Hepatitis A Inflammation of the liver fatigue, fever, loss of appetite, right-sided abdominal pain, dark colored urine clay colored feces, and jaundice - fast food restaurants that do not have good hygiene among cooks - vaccine available Rotavirus vomiting and slight fever, followed by profuse watery diarrhea - contaminated water source oral-fecal route common among children most children have built up an immunity by age 5 vaccine was on market for short time pulled off the market in Norwalk virus - Cruise ship disease contaminated shellfish -

60 Cases of hepatitis A Figure 24.18

61 Transmission electron micrograph of rotavirus Figure 24.16

62 Electron micrograph of Norwalk virus Figure 24.17

63 Comparison of Hepatitis Infections A B C Transmission Food Blood-STD Transfusion Type of Virus Severity Picornavirus - RNA Mild Hepadnavirus - DNA Severe Flaviviridae - RNA Severe Frequency Vaccine Available? Most common Yes Second most common Yes Least common - increasing No

64 Figure Hepatitis B virus